The investigator will study and describe the careers of 248 male opioid drug users in San Antonio. The men were selected as research subjects when they were hospitalized for treatment of opioid dependence during the years 1964 through 1967. Retrospective and prospective data collection began in 1966; prospective data collection continues in 1983. Data are collected by periodic interviews with subjects and by review of records of law enforcement, correctional, and treatment agencies. Chronological records of drug and alcohol use, criminal activity, social functioning, health, and treatment and correctional experience are reconstructed for each subject. In addition, data are collected about community conditions affecting opioid use. Subjects are predominantly Mexican American. They began opioid use at the median age of 17; in 1983, if all were alive, the group would have a median age of 45. Continued prospective study will yield important information about a little known period, that after the age of 40, in the career of the opioid user. The project is expected to produce information about the relation of background predictors to long-term outcomes, the consequences of multiple treatment and correctional interventions, the frequency and correlates of prolonged abstinence (recovery) and relapse, and the substitution of other disabling symptoms.